Abstract

The DANSS experiment is a scintillation spectrometer of reactor antineutrinos placed at the Unit 4 reactor of the Kalinin Nuclear Power Plant about 300 km northwest of Moscow. The main fundamental aim of the experiment is search for sterile neutrinos. The experiment was commissioned in April 2016 and regular data taking has been carried out since October 2016. 7.7 million of inverse beta-decay events have been collected by March 2023. A vast exclusion area of the sterile neutrino parameters was set. In the region of the best sensitivity the limit reached \({\text{sin}}2{{\theta }^{2}} = 5 \times {{10}^{{ - 3}}}\). The reactor power has been monitored for 6.5 years. The dispersion that is not related to single measurement statistics is below 0.5%, which gives an upper estimate of the precision of the standard NPP power measurements at the level of at least 0.5%. New scintillator detectors designed to upgrade the DANSS facility were tested at an accelerator beam. Light yield better than 140 ph.e./MeV was obtained. This paper describes the results obtained during the last year and the facility upgrade plans.

中文翻译：

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DASS 实验：最新结果和展望

摘要

DANSS 实验是一台反应堆反中微子闪烁光谱仪，放置在莫斯科西北约 300 公里的加里宁核电站 4 号反应堆中。该实验的主要基本目的是寻找惰性中微子。该实验于2016年4月启动，自2016年10月起定期采集数据。截至2023年3月，已收集了770万个逆β衰变事件。设置了广阔的惰性中微子参数排除区域。在最佳灵敏度区域，极限达到\({\text{sin}}2{{\theta }^{2}} = 5 \times {{10}^{{ - 3}}}\)。反应堆功率已监测了6.5年。与单次测量统计无关的离散度低于0.5%，这给出了标准NPP功率测量精度至少在0.5%水平的上限估计。为升级 DANSS 设施而设计的新型闪烁体探测器在加速器束上进行了测试。获得了优于 140 ph.e./MeV 的光产率。本文介绍了去年取得的成果以及设施升级计划。